Fuse receptacle



March 27, 1934.

G. E. WADSWORTH 1,952,151

FUSE RECEPTACLE Filed Oct. 30, 1930 2 Sheets-Sheet l A TTORNEY:

March 1934- G. E. WADSWORTH 1,952,151

FUSE RECEPTACLE Filed Oct. 30, 1930 2 Sheets-Sheet 2 07 5- was 6o f KJQL A TTORNEYQ Patented Mar. 27, 1934 UNITED STATES PATENT OFFICE FUSE RECEPTACLE George E. Wadsworth, Erlanger, Ky., assignor to The George B. Wadsworth Company, Cincinnati, Ohio, a corporation of Ohio Application October 30, 1930, Serial No. 492,248

Claims. (01. 200119) My invention relates to fuse receptacles of the Figure 5 is a perspective view of my cup-shaped -panel cut-out type. insulating washer.

The ordinary fuse, particularly for the plug Figure 6 is a perspective view of a contact clip type of cartridges, is susceptible of being cirfor the receptacle shell. 5 cumvented by the insertion within the receptacle Figure 7 is a perspective view of the base con- 39 of a coin, a disc of metal or a piece of wire. This tact plate. brings-about a highly undesirable condition which Figure 8 is a perspective view of a receptacle is likely to cause fires, due to short circuiting shell. of electrical apparatus in various parts of the Figure 9 is a sectional view taken along the establishment, and is also very likely to cause selines 99 of Figure 10. rious accidents, due to shocks which are re- Figure 10 is a front elevation of the mounting ceived either during the attempt to insert the cabinet on a slightly reduced scale from that metal piece which is to circumvent the fuse, or shown in Figures 1 to 3. because of current over-charging some of the Figure 11 is a bottom plan view of the reelectrical equipment which is supplied with curceptacle and its mounting base, being taken from rent. the bottom side of the view shown in Figure 2. The ordinary plug fuse consists of a receptacle I have shown a panel composed of a pressed, :with'a metal shell and with a central pin which open-front metal case 1, with a front panel 2 the tip of the fuse is supposed to bear against. secured thereto and held in position as with To replace an exhausted fuse, all that is necesscrews 3. Openings 4 are provided in the sides 79 sary is to insert some metal piece within the plug of the case for the installation of the electrical socket which extends across between the central conduits. A front cover 5 having an outwardly pin'and the outer receptacle. extending portion 6 is hinged to the front panel It is the object of my invention to provide a as with hinges 7. Openings 8 are further profuse receptacle in which no fuse other than the vided in the front panel through which the outer standard plug type of fuse can be employed. It end of the fuse receptacles extend. is a further object to provide a receptacle in which Referring now to the construction of the fuse electrical connection between the fuse and the receptacle itself, a mounting panel 9 of insulative contact members will not occur until such time material has annular extensions 10 preferably as the plug fuse is completely screwed home. formed integral therewith. The annular mem- Another object is the provision of a fuse recepbers 10 have openings 11 through which the electacle in which the contact members are ordinarily trical contact plates may be extended.

dead until such time as the fuse is inserted. The outer shells 12 are mounted on the panel Broadly, therefore, it is my object to provide within the annular members 10 by means of cona fuse receptacle in which nothing but an autact plates 13 and screws 14 extend up from -re- 99 thorized fuse may be used and in which, regardcessed holes in the panel and engage threaded less of an attempt to tamper with the receptacle holes 15 in the Contact members th y and circumvent the fuse no accident can be firmly securing the outer contact shells within caused because until the fuse is inserted, the electhe insul-ative annular members T i r trical contact members will not cause a shock. ends of the f '13 provldefi t The above Objects and other objects to which threaded holes 16 as shown in Fig. 6, which seat reference will be made in the ensuing disclosure, to whlihdthe wlres of the I accomplish by that certain combination and (mom ale or many connec e Within the contact shell there are mounted arrangement of Parts of Whlch I have shown a cup-shaped washers 17 composed of dielectric 109 preferred embodiment.

material, and the cup-shaped washers may be Referrmg to'the drawmgslf retained in position by extending the-screws 14 Figure 1 is a perspective Vlew of a panel through the apertures 18 in the panel 9 into out fuse receptacle. tapped holes in the bases of the cup-shaped Figure 2 is a plan view of the fuse receptacle h detached from the mounting cabinet. A contact plate 19 which fits within an open- Figure 3 is a sectional view taken along the ing 20 in the base of the panel, is connected'by lines 3-3 in Figure 2. means of screws 21 to a plate 22 which carries Figure 41s a side elevation of the central spring a terminal screw 23 to which the line connection contact pin. may be made. The plate 19 is, as indicated, 1w

mounted in recessed position within the panel block and provides the electrical contact with the middle pins 24 against which the tips of the plug fuses contact. The pins 24, as indicated in Figure 3, have enlarged heads 25 which seat Within recesses 26 which extend in from the recess 20. The pins also have enlarged contact heads 27 which are urged outwardly within the receptacle, as indicated in the upper receptacle illustrated in Figure 3.

The lower receptacle indicated in Figure 3 shows the connections when a plug fuse is inserted. The plug fuse which I have indicated at 28 threadably engages the shell 12 and gradually presses down on the pin 24 until when the lower end of the fuse is seated as far is as it can be turned, the head 25 of the pin 24 will engage the contact plate 19 and thus permit the current to pass through the receptacle.

As an example of a double branch cut-out plug single fuse wiring diagram, we have indicated such an arrangement in Figures 2 and 3. The line wire, as indicated, extends to the screw 23 and the current passes down through the screws 21 andestablishes a connection with the plate 19. The ground wire may be connected to a terminal screw 29 which threadably engages a metal plate 30 mounted on the base block with screws 31 which preferably are countersimk. and extend up from recessed holes from the lower side of the base or the block 9. The first and second circuits are supplied with current through wires which connected to terminal screws 32 which are threaded into the plate 31.

It will thus be noted that in my construction I have provided a fuse receptacle which will meet with all the standard requirements of the Underwriters specifications, in which the fuse receptacle is dead until such time as the standard type of plug fuse is inserted into the receptacle.

Because of the washers 17 which have the cup shaped annular sides, any fiat piece of metal which it should be attempted to insert into the receptacle WOlllL be insulated from the outer shell by the time it was sufficiently depressed to contact with the plate 19. It will further be understood that while I have illustrated one particular type or" fuse receptacle, various arran ements in wh erent circuit arrangements can be provided will readily occur to those skilled in the art employing the same principle of a normally out-of-contact middle spring It, in some modifications, the member 27 is fixedly mounted and in direct contact with the pate l9, aslong as the washer 17 has the annular skirt extending upwardly in the receptacle beyond the plane of the end of the pin, it will be impossible to insert a coin or washer in place of the regular shaped plug fuse. While such a construction will not have the contact parts dead normally, the use of the washers will prevent unauthorized use of. any other type of fuse in the receptacle than that for which the receptacle is intended.

to receive a threaded connection member such as a fuse plug, with the thre ded parts of the shell and member as connecting terminals, the connection member having a central contact element as poses forth.

its other terminal, an insulating cup-shaped guard member fixed in the bottom of the receptacle and having a central aperture, a central contact element extending through said aperture and yicldingly mounted to rccede toward the bottom of the guard member, said connection member central contact element contacting with the yieldingly mounted contact element when the connection member is screwed down into the receptacle and causing the recession of the yieldingly mounted element, and said receptacle comprising a base into which said yieldingly mounted element has an extension, and a contact member mounted in said base and contacted by the yield ing contact element when the latter recedes, said guard member being deep enough to hinder direct connection of the yielding contact element and the receptacle shell by means other than the inserted connection member, without being so deep as to require special extension of the central contact element of said inserted connection member when the yielding contact element is in receded position.

2. Areceptacle as setforth in claim 1, in which the receptacle shell has a bottom inturned part under the guard member, and in which the guard and said shell are held in position by a fastening elezner passing up into .the guard member from the receptacle base.

3. A receptacle as set forth in clam l, in which the contact member mounted in the base is yielding to the receding contact member, and in which there is stop means at the bottom of the guard member, engaged by the central contact element of the inserted connection member to positively limit the degree of passage of the lattermember into the receptacle.

4. A receptacle as set forth in claim 1, in which the base has an upper and a lower space around the extension of the receding contact element,

and in which the yielding mounting of the latter element consists of a spring mounted in the upper space, said extension having an enlargement in the lower space guidingly fitting said lower space and limiting upward protrusion of the receding element by contact with the top of said space.

5. In a receptacle comprising a contact shell to receive inclectrical contact the outer shell of an inserted connecting inserted device, which device also has acenter contact element extending only a slight distance past the inner end oi its shell in proportion to the diameter of its shell, said receptacle having an aperture in its bottom, a relativelywide shallow annular guard lying close to the il'll'lfii end portion 01": the receptacle contact shell, and outstanding around said aperture, a center contact element for the receptacle extend-- ing through theaperture and the guard, to receive in electrical contact the center contact element of the insert-e. device, mounted to recede into the guard under pressure of the inserted devicefand contact means wi wl on said center contact element of the receptacle is normally out of contact, but with which it nak'es contact when it recedes, said guard being of such depth as to allow substanti y only the necessary inward movement of e i ted device to complete said contact before the outlying portions of the inserted device engages the rim of the guard, for the pur- GEORGE E. XNADSWORTH. 

